This application aims to develop a tool for rapid and comprehensive analysis of complex mixtures of triglycerides (TAGs). The fats in our diet are primarily composed of triglycerides, and diets high in fats have been implicated in a host of common medical conditions, including heart disease, obesity, insulin resistance, and hypertension. Triglycerides are composed of three fatty acids attached to a glycerol backbone. Analysis of complex mixtures of triglycerides is generally performed by cleaving the fatty acids from the glycerol moiety and determining the overall fatty acid composition of the TAG mixture. However, recent data suggests that the fatty acid position along the glycerol backbone affects TAG metabolism. Methods for rapid and comprehensive quantification of individual TAGs species are needed to support research on the relationship between TAG metabolism and heart disease. We are proposing to construct a derived-library of collisional-induced decomposition mass spectra for TAGs of any fatty acid composition and positional arrangement. This will be accomplished by synthesizing a large array of positionally pure TAGs that can be used to model TAG fragmentation. The library will be incorporated into a reversed-phase high performance liquid chromatographic-electrospray tandem mass spectometric platform to support the automated analysis of individual TAG species in complex mixtures. [unreadable] [unreadable] [unreadable]